Method of and apparatus for ampoule inspection



Apri] 14, 1953 E. w. KELLOGG E1 AL 2,635,194

METHOD OF AND APPARATUS F OR AMPOULE INSPECTION Filed May 27, 1949ATTOR'NY Patented Apr. 14,- 1953 Edward W. Keuogg and Lawrence T.sachnebenf d Haddonield, and James Price, Erlton, N. 3.,; assignors toRadio Corporation, of America,a

corporation of Delaware Applicationll/Iay, 1949, Serial N0.V95,818

l Thisinvention relates to a method of V74and apparatus forinspecting'the contentsof light transmitting cyclindrically shapedbodies, such as medic'al-ampules. More particularly, the inventionrelates to a method of and apparatus for inspecting the contents ofindividual ampules for the presence of contaminating particles.

Serums and other liquids intended for therapeutic use are frequentlypackaged in small, hermetically sealed, substantially cylindricalcontainers made yof-glass or other transparent malteri'als. It isusually necessary that the contents be of a high degree of purity andfree of anysuspended particles large enough to be visible to the unaidedeye. However, in the processes of manufacturing many of thesemedicinals, many mechanical handling steps, such as filtration, areutilized. Tiny particles or slivers of the ltering medium, 'for example,may be introduced into the liquid, and containers which iny clude suchparticles or slivers must be discarded.

This necessitates very careful inspection by many operators in order todetect and remove from each batch those ampules containing contaminatingsubstances.

'Heretofora this inspection had to be conducted visually and the ampulesseparated into passed and rejected categories entirely by hand.Furthermore, an inspector who had to minutely examine many `units in thecourse of a day was subject to great eyestrain and eyefatigue so thatthere was always present the danger `of vpassing ampules whichshould'have been Vrejected because of the presence of contaminatingmatter.

The present invention,` although not designed for completely automatichandling of the ampules, eliminates the necessity for the visualrinspection and provides a rapid means for electronically inspectingeach unit for particles which maybe either more or less dense than ltheliquid in which they are present.

Briefly, the essential feature of the invention is Athefemployment of anovel apparatus and method for spinning an ampule just prior toinspection :and for holding the ampule in position duringthe 'inspectionperiod without interfering with the passage of a beam of lighttherethrough. This is accomplished by Aproviding a pair `of drivenrollers with an opening therebetween, and adapted to impart rotationalmotion to the ampule when the ampule is in frictional Vcontact with therollers. A beam .of light is kpassed through the .opening and thencethrough the ampule, and light leaving the ampule is directed 4 Claims.(Cl. Z50- 218) to a photocell. A dierential in air'pressure is createdon either side of the opening between the rollers, and this servestoincrease the -frictional contact between the ampule and thehrollers sothat the ampule, even though in an upright position, can be rotatedrapidly, abrupt: ly halted, and inspected without'utilizing any furthermeans for holding the ampule in position. Withv some ampules, however,`an additional meansto hold theampules while spinning is desirable, and amechanical ejector may be used to free the ampule from the holding eiectof the air pressure after the inspection-period is over.

Gne object of the present invention is to provide an improved apparatusfor electronically inspecting the contents of individual,lighttransmitting, liquid-filled containers, having a generallycylindrical shape.

Another object of the invention is to provide an improved method ofelectronically inspecting the contents of individual,light-transmitting, liquid-filled containers for the presence ofcontaminating particles.

Another object of the invention is to provide an improved apparatusespecially adapted to inspect electronically the contents of relativelysmall containers filled with liquid.

Another object of the invention is to provide an improved-apparatus forinspecting the contents of relatively small, liquid-filled medicalampules while the contents are rapidly whirling within the container.

Another 'object of the invention is to provide an improved apparatus forimparting a whirling motion to the contents of Va liquid-lled ampule and`inspecting the whirling contents electronically, without interferingwith the passage of a beam of light passing through the ampule.

Another object of the invention is to provide a means of substitutingelectronic inspection for visual inspection of relatively small medicalampules. n 1

A further object of the invention is to provide an improved' means andmethod for holdings. small cylindrical body during a spinning operation,and means for releasing the body at the end of an operational period.

Still another object ofthe invention is to -provide Yan improved methodand apparatus for spinning a relatively fragile glass body and holdingit during an inspection process.

These land other objects will be more :apparent and the invention willbe `better understoodw-ith reference to the following description andthe accompanying drawings, of which:

Figure 1 is a plan view, partially in section and partly diagrammatic,of the essential parts of an apparatus which may be utilized to carryout the objects of the present invention,

Figure 2 is an elevation view of part of the apparatus of Figure 1,

Figure 3 is a plan view, partially in section, of a' .a liquid which isWithin a bottle, the method including holding the bottle betweenrotatable chucks, rapidly spinning the bottle between rotatable chucks,rapidly spinning the bottle and its contents, suddenly stopping therotation o! the bottle, and, immediately thereafter, photoelectricallyinspecting the contents of the bottle -While the liquid is stillrotating but while the bottle is stationary. A beam of light is focussedat a plane cutting through the bottle and the light is ldirected throughthe bottle to a photoelectric cell on the other side. Any particle ofcontami- Ynating matter suspended in the liquid moves rapidly back andforth through the light beam due to the whirling motion of the liquidand a signal is produced in the output circuit of the photocell due tointermittent interruption of the passage of part of the light. Thecharacteristics of the bottle, itself, do not influence the results oithe inspection since the bottle is stationary during the inspectionperiod and since the inspection apparatus responds only to intermittentinterruption of the light beam.

The previously used apparatus, which has been designed to utilize theabove described method, operates very well when the liquid containersare relatively large and have considerable structural strength. However,the apparatus disclosed in the said Stout patent and in those patentsdirected to improvements thereon is not adapted to handle relativelysmall objects such as medical ampules, which may have a volume of only 1t 10 cc. and which may be only 1 to 3 inches in length and about 1A; to3A of an inch in diameter. Moreover, medical ampules are usually quitefragile with relatively thin walls. Accordingly, the present inventionhas been developed to utilize the basic inspection method describedabove but to apply it to the inspection of the contents of relativelysmall containers of a fragile nature.

Referring, now, to Figure 1, there has been provided a vacuum chest 2which may be made of any suitable material, such as sheet metal. Thischest has a box-like portion 4, having side, back, bottom, and top walls6 generally square or rectangular in outline. The front wall 8, of thechest, is provided with a protruding bay l0. The front wall I i of thebay is provided with an opening l2 in the form of a narrow slit and mayalso b eprovided with additional openings I4 and I6, spaced adjacent thecentral slit.

One of the sidewalls is provided with an openingl' leading to a conduit20, which is connected to means 22 for creating a reduced pressurewithin the chest. The means for creating the reduced pressure may be anydevice, such as a suction fan, which is adapted to produce a low vacuum.

Two cylindrically shaped rollers 24 and 26, having surfaces 28 of aresilient material, such as rubber, are mounted on the front of the bayIll such that one is positioned on either side of the slit I2. Anopening 30 is provided between the rollers which are spaced apart adistance approximately equal to the width of the slit. The rollers arerotatably mounted between a top bracket 32 and a bottom bracket 34 andare spaced just far enough from the front wall Il of the bay such thatthey are free to rotate. Each roller is provided with an axle 36 whichrotates within top and bottom ball-bearings 38 and 4U, carried by thetop and bottom mounting brackets 32 and 34, respectively.

Means, now to be further described with reference to Figure 2, is alsoprovided for driving both of the rollers in the same direction. Each ofthe axles 36 of the rollers extends downward through the bottom bearings40 andhas a downwardly protruding portion 42 extending beyond the lowermounting bracket. Each of the protruding portions is provided with athickened sleeve 44. Bearing against both sleeves is a rubber tireddriving Wheel 4B, which is rotated by means of a shaft 48 driven bymotor 50. The motor is connected to a power source (not shown) and maybe turned on and off by means of a key, or switch, 52. The motor ispreferably a universal type having brushes and commutator. Since thedriven partsV are relatively light in weight andiit tightly, theirmotion can be started and stopped relatively abruptly.

A light source and optical systems are provided within the vacuum chest.'I'he light source may be a lamp 54 mounted adjacent the end oi thechest opposite the bay I0.. Between the light source and the centralslit l 2, which serves to dene the light beam, is an optical systemcornprising a set of condensing lenses 56, another optical slit 5.8, anda cylindrical lens '60, which system is for the purpose of focussing thebeam from .the light source at a plane just beyond the opening betweenthe rollers.

The remainder of the complete optical system comprises another set oflenses 62, positioned beyond the rollers outside the vacuum chest, whilethe inspection device is a photoelectric cell 64 having a conventionaloutput circuit 66, which is connected t0 an indicating device 68, suchas a signal light or buzzer. It is preferable, of course, to shield thephotocell from the effects of stray light and spurious reflections.

The operation of the device is as follows. An ampule 10, containingliquid, is placed over the opening 30 in frictional contact with theresilient outer walls 28 of the rollers 24 and'26. At the same time, thesuction means is placed in operation such that there is a suction ofabout 0.5 to 1 ounce per square inch at the opening between the rollers.Since there is a lowered airpressure just within the opening between therollers, the ampule is held in position against the rollers by therelatively higher outside atmospheric pressure pressing against theampule. The slits `|4 and-i6.' positioned on either side of the opticalslit l2 enable a larger volume of air to be drawn throughA the vacuumchest. The differential in air pressure may also be said to increaseVthe frictional contactgbetween the ampule and the rollersso that theampule is held rmly against the'rollers'." Therollers are then spunrapidly for a short `.:pe'rioizi:of time. tflhisicausesxthefampuleiandiits contentsftowrotaterapidly; also. lTherotation `of the rollers iis athen abruptlyxstopped by .stoppingrrlthesmotor. 50. The rotation; ofat-heampule is, also, `rof course,suddenly "halted, .but ftheliquid continues-itc `:whirl fior-a, time dueitoaitsiownlinertia.

During'this period, the inspection system :is in :operation fand, ir #a:particle lof' `suiii'cient-size ris ate a*suitable i mechanism to."indicate `that the ampule should be'rejected. "Thisfmaybefa signal{light or buzzer or may "be an Vani-,climatic sepl"grating 4dev-ice ofconventional design -which di- 'greets Aall massed tampules to onereceptacle-.and

-After the end of the inspection period'jthe-suc- "tion'may bereleasedeither bystopping the Opelation of the suction device or by`closing a lvalve l2 inthe'suction conduit 20. The 'ampule will 4then'drop laway from the Arollers intofany receptacl'e AI3provi'ded tovreceive it.

' The "above 4described 'apparatus functions" well with Asmall ampuleshaving -`a diameter `which is jsubstantielly-uni'form. Because ofthemeans'employed for holding the ampule 4while spinning andinspectingit,'there `is nothing to interfere with'thepassage of the 'light "beamthrough the center of the ampule. lInaddition, the apparatus isadapted-to hold the fragile ampule without applying any "heavyforoe toits wallswhich would result in a` largepercentageof breakage- Chucks forholding the ampules had previously been tried buto necessity producedsome obstruction of the light close-to the bottom of the ampule, thevery place where foreign particles are Vmost likely t bepresent. Also,the widely varying sizes of the xampules and their peculiar shape, dueto the presence of "a sealing-oi protuberance, makes it extremelycdifiicult to designa practicalehuck.

'Whenthe `ampules are not of substantiallyuni- Viforxn diameter, and areofthe larger sizes'.` a modi- ;doationof the apparatus, such asfshownxinFignure 3, :has been found advantageous. As Nillustrated in the figure,a movable arm 14 carrying three small idler rollers 16, 18, and 80 maybe swung into position during the spinning Operation such that the idlerrollers bear against the wall of the ampule and assist the suctiondevice in holding the ampule against the surfaces of the drivingrollers. At the conclusion of the spinning cycle, the idler rollers areswung out of the Way by the arm 14 so as not to interfere with theinspection step. This may be accomplished either manually orautomatically in the embodiment which is now to be described. The arm14, carrying the idler rollers, is pivoted on a pin 82 located at oneside of one of the driving rollers 24 such that the arm and the rollerscan be swung out of the path of the light beam passing through thecenter of the ampule. The arm is provided with a short branch 84integrally joined thereto at right angles. The branch is pivotallyconnected to a link 86 which, in turn, is pivotally joined to a plunger8B extending through a solenoid 90. The end of the plunger is providedwith a button 92y to which a spring 94 is connected. The other end ofthe spring is fastened to a fixed plate 96 through which the solenoidplunger also passes. When the solenoid has no current passing throughit, the spring pulls the plunger forward and this motion is translatedto the arm "M, movn.ing'itfaroundinia;swingingmotionsuch-thatlthe (from:a power r'source tnotJshown), ,fas by pressing fa key 9 8,` and `this ipullsnthe i plunger whack '.into

the solenoid, ,which faction, in turn, swings "the `.arm l lia-ndztheidlerrollers :outfofthepath/ofthe light beam passing 4:through 'thecenterV of v`the ampule to the position,shown'sinligurei6. The solenoidmaybe actuated 'by vany conventional means such asa' manual contact.switch, as'shown, or automatically 'operated 'byarelay'tnot shown) Thedifference inpressure onfeither "sidefoffthe opening-betweentheirollersl 30 may-'also'becreated in a diierent"'manner. Instead foffapplyingfsuction'through the: openingfa'streamof compressed air may bedirected vtoward-s the *opening from the outside. An objectplacedacrosslthe opening will thus be held on vthe rollers bytheincreased airV pressure directed against its-'exposed walls. This is notas satisfactoryyhowever,fasthepreviously describ'edembodiment. j

Although the ampule may be released'fromthe rollers at the end of theinspectioniperiodbyfcutting off the suction in themannerpreviously'described, it is possible-to release the fampulewithoutcutting oli lthe suction,ina `manner-"which 'is now to beV described.

Referring now to Figure- 5, "ther'e is 'show-n an ampule l0, being heldagainst rollers `2li` 'and'26 by means of a diierential in air pressurewhich may be maintained Vby'meansfsuch aspreviously described. Idlerrollers 16,"18andnimay'also'be swung into-position against the ampule toaid in holding it against the rollers duringfthe timethe ampule is beingspun. `When larger diameter ampules are being spun, thetwoouter idlerrollers 16 and 80 make `contactwiththe wallsof the ampule. Whenl'ampules ofthe smallest diameters are spun, only the vcenteridler "18makes Contact with the ampule. 'The ampuleejectin'g apparatus comprisesan ejectorarm |100, positioned between and immediately behind vztheampule spinning rollers'24 4and V26,"th'e lowerfend of the arm beingprovided with a toe `portion-'102 extending forwardly through theopening 30 between the rollers.

The ejector arm is provided with means for lmparting reciprocatingvertical motion thereto. This means may comprise a horizontal lever arm|04, plvoted about a centrally positioned fulcrum |06, with one end ofthe lever arm being pivotally connected to the top end of the ejectorarm and the other end being pivotally connected to the lower end of aplunger |08, which is adapted t0 be drawn upwards against the biasingaction of a springr H0, by a solenoid H2, which may be energized byclosing a key switch I I4, using a conventional power source (notshown). The spring is adjusted to normally hold the plunger at thedownward extremity of its stroke when the solenoid is not energized.

During the period in which the ampule is being spun and the following.period in which the ampule is stationary but the contents are stillspinning, the ejector arm is held at the upward extremity of its strokeso that it does not interfere with the passage of the inspection beamthrough the ampule. This position is illustrated in Figure 5.

Immediately after the rollers 24 and 26 have stopped spinning and justprior to the start of the inspection period, the idler solenoid isdeenergized, whereupon the idler rollers are swung away fro-m the'ampule as previously described. The inspection period then follows.

vImmediately following the inspection period,

.the solenoid is actuated, drawing the plunger 108 upward and moving theejector arm downward Y(as shown in Figure 6), whereupon'the forwardlyextending toe I 02 pushes against the ampule and -kicks it forward, awayfrom the ampule-spinning .against a pair 'of rollers by a force createdby a differential in air pressure between two dierent points on itsexternal surface and the object is then spun by driving the rollers. Atthe end of the operational period, the object may be released from itscontact with the rollers by producing a sufficient force in oppositionto the force which is due to the differential in air pressure or elsebyshuttingl oli?v the means which produced the pressure differential.The opposing force v.may be either an ejector arm or any othermechanical-equivalent such as a reverse air blast. Various othermodifications in the apparatus may also be made within the spirit of theinvention, which has a particular application to the method ofinspection described.

We claim as our invention:

1. Apparatus for inspecting the contents of a transparent containerhaving substantially cylindrical side walls, including a pair of drivenrollers having an opening therebetween and adapted to impart rotationalmotion to said container when said walls are in frictional Contact withsaid rollers, means for passing a beam of light through said opening andthrough said container, means for creating a dilerential in air pressureon either side of said opening whereby the frictional contact of saidwalls with said rollers is increased, and auxiliary means for holdingsaid container against said rollers while said container is rotating.

48 2. Apparatus according to claim 1 including means for moving saidauxiliary'holding lmean out of the path of said beam of light.

3. A method of inspecting the iiuid contents of a transparent containerhaving substantially cylindricallyV shaped side walls. said methodcomprising holding said walls in frictional contact with a pairof-rotatable rollers by means of a differential in air pressure betweendifferent points on said walls, rotating saidv container and itscontents' by rotation of said rollers, 4stopping the rotation of saidcontainer while the contents remain in rotation, andphotoelectricallyinspectring said rotating contents. l

n 4. A method of inspecting the iiuid contents of a transparentcontainerhaving substantially cylindrically shaped side walls, saidmethod comprising holding said walls in frictional contact with a pairof rotatable rollers by means of a force created by the differential inair pressure between different points on said walls, rotating saidcontainer and its contents by rotation of said rollers, stopping therotation of said conr tainer while the contents remain in rotation,photoelectrically inspecting said rotating contents, and releasing saidcontainer from said contact with a force in opposition to the forcecaused by said dilerential in air pressure. EDWARD W. KELLOGG.. LAWRENCET. SACI-ITLEBEN. JAMES F. PRICE.

References cited m the me of this patent i UNITED STATES PATENTS NumberName f' Date A 1,003,786 Pecht Sept, 19, 1911 1,333,006 Welser Mar. 9,1920 1,553,760 Ellis Sept. 15, 1925 1,836,690 Talbot Dec. 15. 19311,871,430 Snow Aug. 9, 1932 1,926,466 Twohy Sept. 12, 1933 2,021,696Millerv Nov. 19, 1935 2,079,833 Bennett May 11, 1937 2,192,580Sachtleben Mar. 5, 1940 2,255,034` Bauer Sept. 2, 1941 2,436,082 StoutFeb. 17', 1948

